Why did Lucy Snowe leave London in Charlotte Bronte's novel Villette?

I'm curious about this. It seemed like it was this big adventure to travel to London, but then the next day before dusk she is leaving on a boat for Brussels. The novel begins a little slow and confusing but I stuck with it, but this part really confused me. I am only on Chapter 9, presently, but this question keeps distracting me as I read on.

Why did she suddenly decide to leave London? She spends the night, wakes up on her first morning in London.. walking alone she experiences 'elation and pleasure in her heart'. She goes to a bookseller and buys a book, an extravagance... "prodigious was the amount of life I lived that morning" ... "I saw and felt London at last."

She seems in love with the city or 'deeply excited'. She's faint with hunger at 2pm and goes back to the Inn to lunch...a lunch so satisfying compared to all her meals with Miss Marchmont...falls asleep (on three chairs?!) and then she 'thought for two hours'. (we are not much privy to her thoughts)

She doesn't want to return from where she came... which is understandable and goes on about how she has 'nothing to lose'... but why not make this new life in London where she seems so happy and inspired? Then before nightfall, she boards a ship to somewhere.... she's clueless (or we are as 'the reader') as to where she's going or why she's going or what she's going to do once there. It all happens in about 2 paragraphs from waking up, loving London and being aboard a ship going somewhere else.

Is this why some reviews say 'she hates her readers' in this book?

I am loving the book.. i have ready Jane Eyre many times and so happy to find this book..even though i feel a bit lost and confused and the sort of 'jumpy-ness' of the novel so far. I mean it feels rushed and perplexing but her use of language is so wonderful and i am so happy to be reading this.